Xml：
1. 标签成对出现
2. 区分大小写
3. 标签要正确嵌套
4.开始部分：<?xml version="1.0" encoding="utf-8"?>
5.只能有一个根节点
6.节点可以有属性
DTD：约束XML文件的节点
Xml解析：
1. dom（文档对象模型）：把解析的xml整个加载到内存，组织成object树。
w3cDom dom4j
from xml.dom.minidom import parse doc=parse("students.xml") 得到整个DOM文档树 root=doc.documentElement 得到根节点 students=root.getElementsByTagName("student") class Student: def __init__(self,name,age,sex,score): self.name=name self.age=age self.sex=sex self.score=score def __str__(self): return "姓名：{0}，年龄：{1}，性别：{2}，成绩：{3}".format(self.name,self.age,self.sex,self.score) people=[] for p in students: student = Student(p.getElementsByTagName("name")[0].childNodes[0].data,p.getElementsByTagName("age")[0].childNodes[0].data,p.getElementsByTagName("sex")[0].childNodes[0].data,p.getElementsByTagName("score")[0].childNodes[0].data) people.append(student) for p in people: print(p)
2. Sax:事件驱动式解析，不会在内存中加载整个文档，只会根据自己编写的事件保存数据
from xml.sax import ContentHandler from xml.sax import parse class Student: def __init__(self,name=None,age=None,sex=None,score=None): self.name=name self.age=age self.sex=sex self.score=score def __str__(self): return "姓名：{0}，年龄：{1}，性别：{2}，成绩：{3}".format(self.name,self.age,self.sex,self.score) student=[] class mysax(ContentHandler): def __init__(self): self.tag=None self.student=None def startDocument(self): pass def startElement(self, name, attrs): self.tag = name if name=="student": self.student=Student() def characters(self, content): if self.tag=="name": self.student.name=content if self.tag=="age": self.student.age=content if self.tag=="sex": self.student.sex=content if self.tag=="score": self.student.score=content def endElement(self, name): if name=="student": student.append(self.student) self.student = None self.tag = None def endDocument(self): pass students=mysax() parse("students.xml",students) for p in student: print(p)
3. 元素树解析(ElmentTree)
from xml.etree.ElementTree import* class Student: def __init__(self,name=None,age=None,sex=None,score=None): self.name=name self.age=age self.sex=sex self.score=score def __str__(self): return "姓名：{0}，年龄：{1}，性别：{2}，成绩：{3}".format(self.name,self.age,self.sex,self.score) people=[] root=parse("students.xml") student1=root.findall("student") for p in student1: student=Student() student.name=p.find("name").text student.age = p.find("age").text student.sex = p.find("sex").text student.score = p.find("score").text people.append(student) for p in people: print(p)